X-ray protective material and process of manufacturing same



Patented Oct. 12, 1926.

UNITED STATES 1,602,688 PATENT OFFICE.

WILLIAM G. LINDSAY, OF NEWARK NEW JERSEY, ASSIGNOR TO THE CELLULOID COMPANY, A CORPORATION OF NEW JERSEY.

x-RAY PROTECTIVE MATERIAL AND PROCESS OF MANUFACTURING SAME.

No Drawing.

This invention relates to bodies or sub- I stances which are impervious to X-rays, and

which may be utilized as a protection against the injurious effects ofsuch radiation.

' In particular my invention relates to '15 which the above described substance has been incorporated so as to render the fabric impervious'to such X-rays. Such fabric may be used to produce articles of apparel which protect the wearer against the rays.

A further object is to provide an improved method for the manufacture of X-ray impervious substance. I

.Other objects will appear from the following specification and claims in which I disclose certain specific embodiments of my invention.

I have discovered that by incorporating with a suitable binding or holding material an element or the compound of an element whose atomic weight is 180 or over the resulting mass is substantially impervious to X-rays. Among the substances which'impart this quality are tungstic oxide, bismuth subnitrate', bismuth oxide, powdered metal lead, lead sulphate and various oxides of lead such as red lead and litharge; thorium oxide and the oxides of uranium, such as for %raionple those having the formulas U0 As a holding material'I may use celluloid or a pyroxylmcompound which may be worked into any shape and ifdesired formed into flexible sheets.

According to one method of preparation I take 100 parts by weight pyroxylin and 185 parts liquid tricresylphosphate; the latter acting as a plasticizing a cut. These materials are worked together w1th a suitable solvent such as methyl or ethyl alcohol-to produce a plastic mass. There is then added .200 to 400 parts bismuth subnitrate or.

any other of the above materials mentioned and the same is'thoroughly worked into the mass. One method of forming plastic masses of this character is given in detail Application filed October 6, 1922.. Serial No. 592,866.

in my U. S. Patent No. 1,430,020, September 26, 1922. The product which consists of pyroxylin, liquid tricresylphosphate and X-ray proof material is worked upon rolls and pressed into blocks. These blocks are then cut or shaved into sheets of the thickness necessary to give the desired imperviousness. vWhere extreme protection is desired the material may be cut as thick as This material itself is durable, water-proof and not easily inflammable.

The sheets produced in this manner may be used in the production of X-ray proof screens or the like or if desired such sheets may be pressed onto a woven fabric and various garments such as coats, jackets or caps may be made therefrom.

As another method of carrying out my invention, pyroxylin and tricresylphosphate may be dissolved in a suitable solvent to produce a solution similar to varnish. The X-ray proof material is then mixed with this solution which is applied to the fabric. Successive applications will build up the coating on the fabric to any desired thickness.

According to a still further method of applying my invention rubber may be substituted for -the liquid tricresylphosphate and pyroxylin, in which case it is simply necessary to dissolve the rubber in a suitable solvent and incorporate therewith the X-ray proof material. As a specific example 100 parts of pure gum Para. rubber may be dissolved in 4000 parts of benzol and 500 parts of red lead added to the solution. The mixture thus produced is spread'on the fabric and the desired thickness built up-by -methods well known to manufacturers of .roxylin composition I may,.if desired, use

a flexible oil or varnish base such as a linseed oil base.

I claim 1. A composition of matter comprising nitro cellulose, tricresylphosphate and a substance impervious to X rays difiused through the mass in sufiicient quantity to 11 render the same substantially impervious to X rays so as to serve as a protection against the injurious eifects of X ray radiation.

2. A composition of matter comprising nitro cellulose, a liquid aromatic phosphate and the-compound of a heavy metal diffused through the mass in sufiicient quantity to render the same substantially impervious to X rays so as to serve as a protection against the injurious eflects of X ray'radiation.

3. Means for furnishing protection against X rays comprising a flexible sheet composed largely of nitro cellulose, in which is incorporated bismuth subnitrate diiiused through the mass in sufiicient quantity to render the same substantially impervious to X rays so as to-serve as a protection against the injurious effects of X ray radiation.

4. A composition of matter comprising nitrocellulose, a liquid aroma-tic phosphate and a compound of an element whose atomic weight is 180 or over, said compound being diffused through the composition in sufficient quantity to render the same substantially impervious to X rays so as to serve as a protection against the injurious effects of X ray radiation.

5. A method of rendering a fabric impervious to X rays, which consists in forming a composition comprising nitrocellulose, tricresylphosphate and a compound which is present in the composition in suflicient quantity to render the same impervious to X rays, and forcing said composition on to the fabno.

6. A composition formed of a, derivative of cellulose and a compound of an element having a substantially high atomic weight and diffused through the composition in sufficient concentration to give extreme protection against X ray radiation through a thickness of one quarter of an inch of said composition.

7. A composition formed of a derivative of cellulose and a material impervious to X rays and diffused through the composition in sufficient concentration to give extreme protection against X ray radiation through a thickness of one quarter of an inch of said composition.

WILLIAM G. LINDSAY. 

